A known inkjet printer is configured to perform printing by ejecting ink from nozzles. The inkjet printer is configured to corrugate a recording sheet along a scanning direction with corrugated plates and corrugated spurs. The inkjet printer is configured to read deviation detecting patterns printed when a recording sheet is in a predetermined position, to obtain amounts of ink landing position deviations. In the inkjet printer, the amplitude of the corrugations of a recording sheet and an average height or level of the recording sheet vary according to the positions of a leading end and a trailing end of the recording sheet fed in a feeding direction. In the inkjet printer, the obtained amounts of the landing position deviations are corrected according to the positions of the leading end and the trailing end of the recording sheet. More specifically, when a landing position deviation amount obtained from the deviation detecting patterns is expressed as “Y”, the corrected landing position deviation amount Y′ is calculated using a formula, “Y′=a·Y+b”, where “a” and “b” are constants. Ink ejection timings from the nozzles are determined based on the corrected landing position deviation amounts.